A vigil is in the works to remember 8-year-old Martin Cobb, killed trying to protect his sister. Martin is known as Marty.

"I just want to hug my Marty Mar," said family friend Niki Dolan.

Police sources tell NBC12, Marty and his sister were playing near the railroad tracks behind their house when a teen began sexually assaulting the 12-year-old girl. They explain Marty tried to intervene and he was beaten to death.

Marty and his sister often spent a great deal of time at Dolan's home.

"Whether it was coming over to play," said Dolan. "Whether it was just to come over and sit on the front porch and have snacks."

Dolan's six-year-old daughter called the two young victims her best friends.

"How do you talk to a 6-year-old about that?" questioned Dolan. "That her best friends are not going to come over and swing with her tomorrow."

That vigil will be held at the family church, Breaking Every Shackle Ministries, off Brandon Road.

"For something of this nature to happen catches us all off guard," said Pastor Ted Hughey, who notes the suspect lived in the community and called the victims friends. "I would not have given it a thought. He seemed mild mannered. When you talked to him he would say 'sir...I'm looking for a job' or 'I'm in school.'"

The teen is now being evaluated at the Tucker Pavilion at Chippenham Medical Center.

The vigil is Saturday evening at 7:30 p.m. The family has set up the "Keys for Marty" memorial fund. We are told the 8-year-old was fond of keys. You can make donations at any Wells Fargo bank location.